Since 2001, donors attending his parties and other contributors have given the California Democrat more than 800 gifts of wine worth about $340,000, according to a CQ MoneyLine study of campaign finance reports.

These donations — including vintages that were personally donated by many prominent winemakers, including Daniel Fetzer and Robert Mondavi — are used to cater Thompson’s fundraising events or put up for auction to bring in additional campaign funds.

“I’ve always done it that way,” said Thompson, who generally holds an event in each of the seven counties in his wine country district every year. “My events have always been fun, and they have showcased the great things that you can find in my district.”

Thompson leads all Members of Congress in raising funds through this legal but unconventional type of fundraising called “in-kind contributions.” Instead of writing checks, donors give assets, services and other things of value to political groups.

Campaigns, parties and political action committees accepted more than $17 million worth of in-kind donations from 2009 to 2010, according to Federal Election Commission records. Individuals are allowed to donate these items so long as they stay within the limits that cap contributions at $2,500 per election.

Thompson, who co-chairs the Congressional Wine Caucus and owns 20 acres of vines himself, said it makes sense that wine makes up such a major percentage of his in-kind contributions because his district consists of counties that are the “epicenter for wine.”

“Every event I have has a silent-auction component,” he said. “It provides a way that people can participate in helping me get re-elected, whether it’s a fishing trip, a wooden bowl, a box of vegetables or a bottle of wine.”

In addition to these vast amounts of wine, Thompson has received an additional $300,000 in auction items since 2001 that make his contribution reports look almost like a bucket list.

Some of these in-kind donations include a jet boat tour, a fishing trip and two-day white-water rafting excursion. Luxury items for bid by the campaign have been a Porsche rental, a bracelet and a pearl necklace; more practical-minded donors could bid on a massage or a mammogram.

While Thompson’s in-kind vino could stock a wine cellar, Rep. Lynn Woolsey has received enough works of art to fill a small gallery. The California Democrat’s campaign received 46 pieces of artwork during the 2010 election cycle totaling almost $56,000.

Most of these in-kind donations were sold at an auction with the funds going to the campaign. At least 38 of these donors were listed as “artists” in disclosure reports, while other items that were put up for bid came from writers and graphic designers. One contribution included a replica lightsaber donated by “Star Wars” creator George Lucas.

In addition to this art, the Woolsey campaign also reported an additional $20,000 of in-kind contributions including photography, flowers and catering at campaign events during the 2010 election cycle.

In-kind contributions are a legal part of American politics and have been around as long as elections themselves. Over the years, they have allowed excited voters to give what they can to support their candidates. The 2010 election cycle had a significant number of these typical contributions as citizens donated millions in campaign signs, food and rent to candidates, parties and PACs.

But the past two years also had their share of unusual in-kind contributions. For instance, people donated 32 birdhouses, birdbaths and birdcages to the National Rural Letter Carriers’ Association PAC.

“It’s an additional tool that our members use to raise PAC funds,” PAC manager Elliot Friedman said, explaining that sometimes these birdhouses are used as prizes for donors. Other unusual in-kind donations listed by the PAC include an Elvis beanie baby, a scarecrow and a turtle (presumably live).

Similarly, a Pennsylvania farmer and his wife gave Rep. Bill Shuster (R-Pa.) a $178 hog that was later listed as being given to charity. A Northbrook, Ill., homemaker donated $1,920 in “helicopter services” to former Rep. Debbie Halvorson (D-Ill.) during her unsuccessful re-election bid.

New York Republican House candidate Greg Ball received $1,250 worth of teeth whitening items for auction from two New York dentists. On the other hand, more than $4,600 in cigars and cigar-related products were donated separately as in-kind contributions to Reps. Frank Guinta (R-N.H.), Steve Israel (D-N.Y.), Ileana Ros-Lehtinen (R-Fla.) and Kevin Yoder (R-Kan.).